Computers have changed significantly in the past ten years, but standard PC Base Units almost always have the following ports:
- IEC Power Connector: this is the port that the electrical cable plugs into. Standard computers use the three-prong model powered at 10 amps.
- PS/2 Mouse/Keyboard: not PlayStation 2, these are analog artifact ports from earlier systems, before USB. They are sometimes used in older setups, or when all available USB ports are full.
- VGA/Digital: these ports connect to the monitor, allowing the computer to show its information visually.
- Ethernet/Modem: modem ports (connecting to telephone landlines) are increasingly rare, having been replaced almost entirely by faster Ethernet ports (looks like a phone plug, but fatter) and wireless routers.
- Audio: these include speaker/headphone, microphone, and other audio ports. These are almost universally in the 3.5m size.
- USB: the most common ports today, the Universal Serial Bus can connect to and adapt many different peripherals. There are six common sizes of USB connector, usually scaled to larger/smaller devices.
These are the most common PC ports. Other ports are often included on Base Unit models but never used; some computers even have legacy ports such as Games, Serial, or Parallel, which have become all-but extinct because of the versatility and speed of USB.